agent-utils 0.1.0

No project description provided

Note that v0.1 is a dramatically new version developed while releases had to be paused over the summer. If you are looking for the old version based on handlebars, you can use v0.0.64, but you should instead try porting over to the much better new version :)

guidance is a programming paradigm that offers superior control and efficiency compared to conventional prompting and chaining. It allows users to constrain generation (e.g. with regex and CFGs) as well as to interleave control (conditional, loops) and generation seamlessly. Here are some important features:

1. Pure, beautiful python with additional LM functionality. E.g. here is basic generation:

from guidance import models, gen

# load a model (could be Transformers, LlamaCpp, VertexAI, OpenAI...)
llama2 = models.LlamaCpp(path) 

# append text or generations to the model
llama2 + f'Do you want a joke or a poem? ' + gen(stop='.')

Do you want a joke or a poem? I'll give you a poem

2. Constrained generation with selects, regular expressions, and context-free grammars.

from guidance import select

# a simple select between two options
llama2 + f'Do you want a joke or a poem? A ' + select(['joke', 'poem'])

Do you want a joke or a poem? A poem

3. Rich templates with f-strings:

llama2 + f'''\
Do you want a joke or a poem? A {select(['joke', 'poem'])}.
Okay, here is a one-liner: "{gen(stop='"')}"
'''

Do you want a joke or a poem? A poem.
Okay, here is a one-liner: "I'm a poet, and I know it."

4. Stateful control + generation makes it easy to interleave prompting / logic / generation, no need for intermediate parsers:

# capture our selection under the name 'answer'
lm = llama2 + f"Do you want a joke or a poem? A {select(['joke', 'poem'], name='answer')}.\n"

# make a choice based on the model's previous selection
if lm["answer"] == "joke":
    lm += f"Here is a one-line joke about cats: " + gen('output', stop='\n')
else:
    lm += f"Here is a one-line poem about dogs: " + gen('output', stop='\n')

Do you want a joke or a poem? A poem.
Here is a one-line poem about dogs: “Dogs are the best.”

5. Abstract chat interface that uses the correct special tokens for any chat model:

from guidance import user, assistant

# load a chat model
chat_lm = models.LlamaCppChat(model_path, n_gpu_layers=-1)

# wrap with chat block contexts
with user():
    lm = chat_lm + 'Do you want a joke or a poem?'

with assistant():
    lm += f"A {select(['joke', 'poem'])}."`

6. Easy to write reusable components

@guidance
def one_line_thing(lm, thing, topic):

    # update the incoming model
    lm += f'Here is a one-line {thing} about {topic}: ' + gen(stop='\n')

    # return our updated model
    return lm 

# pick either a joke or a poem
lm = llama2 + f"Do you want a joke or a poem? A {select(['joke', 'poem'], name='thing')}.\n"

# call our guidance function
lm += one_line_thing(lm['thing'], 'cats')

Do you want a joke or a poem? A poem.
Here is a one-line poem about cats: “Cats are the best.”

7. A library of pre-built components, e.g. substring:

from guidance import substring

# define a set of possible statements
text = 'guidance is awesome. guidance is so great. guidance is the best thing since sliced bread.'

# force the model to make an exact quote
llama2 + f'Here is a true statement about the guidance library: "{substring(text)}"'

Here is a true statement about the guidance library: "the best thing since sliced bread."

8. Easy tool use, where the model stops generation when a tool is called, calls the tool, then resumes generation. For example, here is a simple version of a calculator, via four separate 'tools':

@guidance
def add(lm, input1, input2):
    lm += f' = {int(input1) + int(input2)}'
    return lm
@guidance
def subtract(lm, input1, input2):
    lm += f' = {int(input1) - int(input2)}'
    return lm
@guidance
def multiply(lm, input1, input2):
    lm += f' = {float(input1) * float(input2)}'
    return lm
@guidance
def divide(lm, input1, input2):
    lm += f' = {float(input1) / float(input2)}'
    return lm

Now we call gen with these tools as options. Notice how generation is stopped and restarted automatically:

lm = llama2 + '''\
1 + 1 = add(1, 1) = 2
2 - 3 = subtract(2, 3) = -1
'''
lm + gen(max_tokens=15, tools=[add, subtract, multiply, divide])

1 + 1 = add(1, 1) = 2
2 - 3 = subtract(2, 3) = -1
3 * 4 = multiply(3, 4) = 12.0
4 / 5 = divide(4, 5) = 0.8

9. Speed: In contrast to chaining, guidance programs are the equivalent of a single LLM call. More so, whatever non-generated text that gets appended is batched, so that guidance programs are faster than having the LM generate intermediate text when you have a set structure.
10. Token healing: Users deal with text (or bytes) rather than tokens, and thus don't have to worry about perverse token boundaries issues such as 'prompt ending in whitespace'.
11. Streaming support, also integrated with jupyter notebooks:

TODO: change this image to new version with the example above.

12. High compatibility: works with Transformers, llamacpp, VertexAI, OpenAI. Users can write one guidance program and execute it on many backends (note that the most powerful features require enpoint integration, and for now work best with transformers and llamacpp).

Table of Contents

• Install
• Loading models
  • llama-cpp
  • transformers
  • Vertex
  • OpenAI
• Example notebooks
• Basic generation
• Constrained Generation
  • Select (basic)
  • Regular expressions
    • Regex to constrain generation
    • Regex as stopping criterion
  • Context-free grammars
• Stateful control + generation
  • State in immutable objects
  • Stateful guidance functions
  • Example: ReAct
  • Example: Changing intermediate step of a Chat session
  • Automatic interleaving of control and generation: tool use
  • Gsm8k example
  • Automatic call grammar for @guidance functions
• Jupyter notebook streaming
• Text, not tokens
• Fast
  • Integrated stateful control is faster
  • Guidance acceleration

Install

pip install guidance

Loading models

llama-cpp

Install the python bindings:

CMAKE_ARGS="-DLLAMA_CUBLAS=on" pip install llama-cpp-python

Loading the model:

from guidance import models
lm = models.LlamaCpp(path_to_model, n_gpu_layers=-1)

transformers

Install transformers:

from guidance import models
lm = models.Transformers(model_name_or_path)

Vertex

Todo @Scott: talk about how constrained generation is different for these models

OpenAI

Todo @Scott

Example notebooks

Coming soon

Basic generation

An lm object is immutable, so you change it by creating new copies of it. By default, when you append things to lm, it creates a copy, e.g.:

from guidance import models, gen, select
llama2 = models.LlamaCpp(path_to_model, n_gpu_layers=-1)
# llama2 is not modified, and `lm` is a copy of it with the prompt appended
lm = llama2 + 'This is a prompt'

You can append generation calls to it, e.g.

lm = llama2 + 'This is a prompt' + gen(max_tokens=10)

This is a prompt for the 2018 NaNoW

You can also interleave generation calls with plain text, or control flows:

# Note how we set stop tokens
lm = llama2 + 'I like to play with my ' + gen(stop=' ') + ' in' + gen(stop=['\n', '.', '!'])

I like to play with my friends in the park

Constrained Generation

Select (basic)

select constrains generation to a set of options:

lm = llama2 + 'I like the color ' + select(['red', 'blue', 'green'])

I like the color blue

Regular expressions

gen has optional arguments regex and stop_regex, which allow generation (and stopping, respectively) to be controlled by a regex.

Regex to constrain generation

Unconstrained:

lm = llama2 + 'Question: Luke has ten balls. He gives three to his brother.\n'
lm += 'How many balls does he have left?\n'
lm += 'Answer: ' + gen(stop='\n')

Answer: Seven.

Constrained by regex:

lm = llama2 + 'Question: Luke has ten balls. He gives three to his brother.\n'
lm += 'How many balls does he have left?\n'
lm += 'Answer: ' + gen(regex='\d+')

Answer: 7

Regex as stopping criterion

Unconstrained:

lm = llama2 + '19, 18,' + gen(max_tokens=50)

19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4,

Stop with traditional stop text, whenever the model generates the number 7:

lm = llama2 + '19, 18,' + gen(max_tokens=50, stop='7')

19, 18, 1

Stop whenever the model generates the character 7 without any numbers around it:

lm = llama2 + '19, 18,' + gen(max_tokens=50, stop_regex='[^\d]7[^\d]')

19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8,

Context-free grammars

We expose a variety of operators that make it easy to define CFGs, which in turn can be used to constrain generation. For example, we can use the select operator (it accepts CFGs as options), zero_or_more and one_or_more to define a grammar for mathematical expressions:

import guidance
from guidance import one_or_more, select, zero_or_more
# stateless=True indicates this function does not depend on LLM generations
@guidance(stateless=True)
def number(lm):
    n = one_or_more(select(['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']))
    # Allow for negative or positive numbers
    return lm + select(['-' + n, n])

@guidance(stateless=True)
def operator(lm):
    return lm + select(['+' , '*', '**', '/', '-'])

@guidance(stateless=True)
def expression(lm):
    # Either
    # 1. A number (terminal)
    # 2. two expressions with an operator and optional whitespace
    # 3. An expression with parentheses around it
    return lm + select([
        number(),
        expression() + zero_or_more(' ') +  operator() + zero_or_more(' ') +  expression(),
        '(' + expression() + ')'
    ])

The @guidance(stateless=True) decorator makes it such that a function (e.g. expression) lives as a stateless grammar that does not get 'executed' until we call call lm + expression() or lm += expression(). For example, here is an example of unconstrained generation:

# Without constraints
lm = llama2 + 'Problem: Luke has a hundred and six balls. He then loses thirty six.\n'
lm += 'Equivalent arithmetic expression: ' + gen(stop='\n') + '\n'

Equivalent arithmetic expression: 106 - 36 = 60

Notice how the model wrote the right equation but solved it (incorrectly). If we wanted to constrain the model such that it only writes valid expressions (without trying to solve them), we can just append our grammar to it:

grammar = expression()
lm = llama2 + 'Problem: Luke has a hundred and six balls. He then loses thirty six.\n'
lm += 'Equivalent arithmetic expression: ' + grammar + '\n'

Equivalent arithmetic expression: 106 - 36

Grammars are very easy to compose. For example, let's say we want a grammar that generates either a mathematical expression or an expression followed by a solution followed by another expression. Creating this grammar is easy:

from guidance import regex
grammar = select([expression(), expression() +  regex(' = \d+; ') + expression()])

We can generate according to it:

llama2 + 'Here is a math expression for two plus two: ' + grammar

Here is a math expression for two plus two: 2 + 2

llama2 + '2 + 2 = 4; 3+3\n' + grammar

2 + 2 = 4; 3+3

Even if you don't like thinking in terms of recursive grammars, this formalism makes it easy to constrain generation. For example, let's say we have the following one-shot prompt:

@guidance(stateless=True)
def ner_instruction(lm, input):
    lm += f'''\
    Please tag each word in the input with PER, ORG, LOC, or nothing
    ---
    Input: John worked at Apple.
    Output:
    John: PER
    worked: 
    at: 
    Apple: ORG
    .: 
    ---
    Input: {input}
    Output:
    '''
    return lm
input = 'Julia never went to Morocco in her life!!'
llama2 + ner_instruction(input) + gen(stop='---')`

Input: Julia never went to Morroco in her life!!
Output:
Julia: PER
never:
went:
to:
Morocc: ORG
in:
her:
life: LOC
!!:
.:

Notice that the model did not spell the word 'Morocco' correctly. Sometimes the model might also hallucinate a tag that doesn't exist. We can improve this by adding more few-shot examples, etc, but we can also constrain generation to the exact format we want:

import re
guidance(stateless=True)
def constrained_ner(lm, input):
    # Split into words
    words = [x for x in re.split('([^a-zA-Z0-9])', input) if x and not re.match('\s', x)]
    ret = ''
    for x in words:
        ret += x + ': ' + select(['PER', 'ORG', 'LOC', '']) + '\n'
    return lm + ret
llama2 + ner_instruction(input) + constrained_ner(input)

Input: Julia never went to Morocco in her life!!
Output:
Julia: PER
never:
went:
to:
Morocco: ORG
in:
her:
life: LOC
!:
!:

While constrained_ner(input) is a grammar that constrains the model generation, it feels like you're just writing normal imperative python code with += and selects.

Stateful control + generation

State in immutable objects

Whenever you do lm + grammar or lm + gen, lm + select, etc, you return an lm object with additional state. For example:

lm = llama2 + 'This is a prompt' + gen(name='test', max_tokens=10)
lm += select(['this', 'that'], name='test2')
lm['test'], lm['test2']

Stateful guidance functions

The guidance decorator is @guidance(stateless=False) by default, meaning that a function with this decorator depends on the lm state to execute (either prior state or state generated within the function). For example:

@guidance(stateless=False)
def test(lm):
    lm += 'Should I say "Scott"?\n' + select(['yes', 'no'], name='answer') + '\n'
    if lm['answer'] == 'yes':
        lm += 'Scott'
    else:
        lm += 'Not Scott'
    return lm
llama2 + test()

Should I say "Scott"? yes Scott

Example: ReAct

A big advantage of stateful control is that you don't have to write any intermediate parsers, and adding follow-up 'prompting' is easy, even if the follow up depends on what the model generates. For example, let's say we want to implement the first example of ReAct prompt in this, and let's say the valid acts are only 'Search' or 'Finish'. We might write it like this:

@guidance
def react_prompt_example(lm, question, max_rounds=10):
    lm += f'Question: {question}\n'
    i = 1
    while True:
        lm += f'Thought {i}: ' + gen(suffix='\n')
        lm += f'Act {i}: ' + select(['Search', 'Finish'], name='act') 
        lm += '[' + gen(name='arg', suffix=']') + '\n'
        if lm['act'] == 'Finish' or i == max_rounds:
            break
        else:
            lm += f'Observation {i}: ' + search(lm['arg']) + '\n'
        i += 1
    return lm

Notice how we don't have to write a parser for Act and argument and hope that the model generates something valid: we enforce it. Notice also that the loop only stops once the model chooses to act with 'Finish' (or once we hit a maximum number of rounds).

Example: Changing intermediate step of a Chat session

We can also hide or change some of what the model generates. For example, below we get a Chat model (notice we use special role blocks) to name some experts to answer a question, but we always remove 'Ferriss' from the list if he is mentioned:

from guidance import user, system, assistant
lm = llama2
query = 'How can I be more productive?'
with system():
    lm += 'You are a helpful and terse assistant.'
with user():
    lm += f'I want a response to the following question:\n{query}\n'
    lm += 'Name 3 world-class experts (past or present) who would be great at answering this.'
with assistant():
    temp_lm = lm
    for i in range(1, 4):
        # This regex only allows strings that look like names (where every word is capitalized)
        # list_append appends the result to a list
        temp_lm += f'{i}. ' + gen(regex='([A-Z][a-z]*\s*)+', suffix='\n',
                                  name='experts', list_append=True)
    experts = [x for x in temp_lm['experts'] if 'Ferriss' not in x]
    # Notice that even if the model generates 'Ferriss' above,
    # it doesn't get added to `lm`, only to `temp_lm`
    lm += ', '.join(experts)
with user():
    lm += 'Please answer the question as if these experts had collaborated in writing an anonymous answer.'
with assistant():
    lm += gen(max_tokens=100)

Screenshot here

Automatic interleaving of control and generation: tool use

Tool use is a common case of stateful control. To make it easy to do so, gen calls take tools as an optional argument, where each tool is defined by (1) a grammar that triggers its call and captures the arguments (if any), and (2) the actual tool call. Then, as generation unrolls, whenever the model generates something that matches the grammar of a tool call, it (1) stops generation, (2) calls the tool (which can append whatever it wants to the LM session), and (3) continues generation.

For example, here is how we might implement a calculator tool, leveraging our expression grammar above:

from guidance import capture, Tool
@guidance(stateless=True)
def calculator_call(lm):
    # capture just 'names' the expression, to be saved in the LM state
    return lm + 'calculator(' + capture(expression(), 'tool_args') + ')'

@guidance
def calculator(lm):
    expression = lm['tool_args']
    # You typically don't want to run eval directly for save reasons
    # Here we are guaranteed to only have mathematical expressions
    lm += f' = {eval(expression)}'
    return lm
calculator_tool = Tool(calculator_call(), calculator)
lm = llama2 + 'Here are five expressions:\ncalculator(3 *3) = 33\ncalculator(2 + 1 * 3) = 5\n'
lm += gen(max_tokens=30, tools=[calculator_tool], stop='\n\n')

Here are five expressions:
calculator(3 *3) = 33
calculator(2 + 1 * 3) = 5
calculator(10 / 2) = 5.0
calculator(10 - 1) = 9
calculator(10 * 2) = 20

Gsm8k example

Notice that the calculator is just called seamlessly during generation. Here is a more realistic exampe of the model solving a gsm8k question:

@guidance
def math_with_calc(lm, question):
    # One-shot example
    lm += '''Question: John starts with 2 balls. He then quintupled his number of balls. Then he lost half of them. He then gave 3 to his brother. How many does he have left?
Reasoning:
1. He quintupled his balls, so he has calculator(2 * 5) = 10 balls.
1. He lost half, he has calculator(10 / 2) = 5 balls.
3. He gave 3 to his brother, so he has calculator(5 - 3) = 2 balls.
Answer: 2\n\n'''
    lm += f'Question: {question}\n'
    lm += 'Reasoning: ' + gen(max_tokens=200, tools=[calculator_tool], stop='Answer')
    # Only numbers or commas
    lm += 'Answer: ' + gen(regex='[-\d,]+')
    return lm

question = '''Janet’s ducks lay 16 eggs per day. She eats three for breakfast every morning and bakes muffins for her friends every day with four. She sells the remainder at the farmers' market daily for $2 per fresh duck egg. How much in dollars does she make every day at the farmers' market?'''
llama2 + math_with_calc(question)

Question: Janet’s ducks lay 16 eggs per day. She eats three for breakfast every morning and bakes muffins for her friends every day with four. She sells the remainder at the farmers' market daily for $2 per fresh duck egg. How much in dollars does she make every day at the farmers' market? Reasoning:

1. She lays 16 eggs per day.
2. She eats 3 for breakfast, so she has calculator(16 - 3) = 13 eggs left.
3. She bakes 4 muffins, so she has calculator(13 - 4) = 9 eggs left.
4. She sell the remainder at the farmers' market for $2 per egg, so she makes calculator(9 * 2) = 18 dollars per day.
   Answer: 18

Automatic call grammar for @guidance functions

You can also initialize a Tool with any @guidance-decorated function, and the default call grammar will be like a python call. Here is an example of using multiple such tools in the same gen call:

@guidance
def say_scott(lm, n):
    lm += '\n'
    for _ in range(int(n)):
        lm += 'Scott\n'
    return lm

@guidance
def say_marco(lm, n):
    lm += '\n'
    for _ in range(int(n)):
        lm += 'marco\n'
    return lm

tools = [Tool(callable=say_scott), Tool(callable=say_marco)]
llama2 + 'I am going to call say_scott and say_marco a few times:\n' + 'say_scott(1)\nScott\n' + gen(max_tokens=20, tools=tools)

I am going to call say_scott and say_marco a few times:
say_scott(1)
Scott

say_marco(1)
marco

say_scott(2)
Scott
Scott

say_marco(2)
marco
marco

Jupyter notebook streaming

example here

Text, not tokens

The standard greedy tokenizations used by most language models introduce a variety of subtle and powerful biases, which that can have all kinds of unintended consequences for your prompts. For example, take the following prompt, given to gpt-2 (standard greedy tokenization):

hf_gen(prompt, max_tokens=10)

from transformers import pipeline
pipe = pipeline("text-generation", model="gpt2")
def hf_gen(prompt, max_tokens=100):
    return pipe(prompt, do_sample=False, max_length=max_tokens, return_full_text=False)[0]['generated_text']

prompt = 'http:'
hf_gen(prompt, max_tokens=10)

' //www.youtube.com/watch'

Notice how Note that the output generated by the LLM does not complete the URL with the obvious next characters (two forward slashes). It instead creates an invalid URL string with a space in the middle. Why? Because the string :// is its own token, and so once the model sees a colon by itself, it assumes that the next characters cannot be //; otherwise, the tokenizer would not have used :, and instead would have used ://. This is why there are warnings about ending prompts in whitespace, but the problem is way more pervasive than that: any boundary that may span multiple tokens will cause problems, e.g. notice how a partial word causes incorrect completion:

prompt = 'John is a'
hf_gen(prompt, max_tokens=5)

' former member'

prompt = 'John is a fo'
hf_gen(prompt, max_tokens=5)

'etus'

While problematic enough for normal prompts, these problems would be a disaster in the kinds of prompts we wrote in this readme, where there is interleaving of prompting and generation happening multiple times (and thus multiple opportunities for problems). This is why guidance implements token healing, a feature that deals with prompt boundaries automatically, allowing users to just think in terms of text rather than tokens. For example:

from guidance import models
gpt = models.Transformers('gpt2')
prompt = 'http:'
gpt + prompt + gen(max_tokens=10)

http://www.youtube.com/watch?v=

prompt = 'John is a fo'
gpt + prompt + gen(max_tokens=2)

John is a former member,

Fast

Integrated stateful control is faster

We have full control of the decoding loop in our integration with transformers and llamacpp, allowing us to add control and additional prompt without any extra cost.
If instead we're calling a server, we pay the extra cost of making additional requests, which might be ok if the server has caching, but quickly becomes impractical if the server does not have fine-grained caching. For example, note again the output from the gsm8k example with calculator above:

Reasoning:

1. She lays 16 eggs per day.
2. She eats 3 for breakfast, so she has calculator(16 - 3) = 13 eggs left.
3. She bakes 4 muffins, so she has calculator(13 - 4) = 9 eggs left.
4. She sell the remainder at the farmers' market for $2 per egg, so she makes calculator(9 * 2) = 18 dollars per day.
   Answer: 18

Every time we call calculator, we have to stop geneation, append the result to the prompt, and resume generation. To avoid slowing down after the first call, a server would need to keep the KV cache up to '3 for breakfast, so she has calculator(16 - 3)', then roll forward generation from that point on. Even servers that do have caching typically have a cache per prompt, and would not be able to do this. Instead, they would consider everything as a new prompt (causing significant slow downs every time calculator is called).

Guidance acceleration

In addition to the benefit above, guidance calls are often faster than running equivalent prompts the traditional way, because we can batch any additional text that is added by the user as execution unrolls (rather than generating it). Take the example below, where we generate a json with llama2:

@guidance
def character_maker(lm, id, description, valid_weapons):
    lm += f"""\
    The following is a character profile for an RPG game in JSON format.
    ```json
    {{
        "id": "{id}",
        "description": "{description}",
        "name": "{gen('name', stop='"')}",
        "age": {gen('age', regex='[0-9]+', stop=',')},
        "armor": "{select(options=['leather', 'chainmail', 'plate'], name='armor')}",
        "weapon": "{select(options=valid_weapons, name='weapon')}",
        "class": "{gen('class', stop='"')}",
        "mantra": "{gen('mantra', stop='"')}",
        "strength": {gen('strength', regex='[0-9]+', stop=',')},
        "items": ["{gen('item', list_append=True, stop='"')}", "{gen('item', list_append=True, stop='"')}", "{gen('item', list_append=True, stop='"')}"]
    }}```"""
    return lm
a = time.time()
lm = llama2 + character_maker(1, 'A nimble fighter', ['axe', 'sword', 'bow'])
time.time() - a

Output

Everything that is not green is not actually generated by the model, and is thus batched (much faster). This prompt takes about 1.2 seconds on an A100 GPU. Now, if we let the model generate everything (as in the roughly equivalent prompt below), it takes roughly 2.67 seconds (not only is it slower, we also have less control over generation).

@guidance
def character_maker2(lm, id, description):
    lm += f"""\
    The following is a character profile for an RPG game in JSON format. It has fields 'id', 'description', 'name', 'age', 'armor', weapon', 'class', 'mantra', 'strength', and 'items (just the names of 3 items)'
    please set description to '{description}'
    ```json""" + gen(stop='```')
    return lm
a = time.time()
lm = llama2 + character_maker2(1, 'A nimble fighter')
time.time() - a

Output, roughly the same, but much slower.